An Overlay Architecture of Global Inter-Data Center Networking for Fast Content Delivery

Content Delivery Network services, which were originally aimed at achieving fast content delivery, began being used for fast delivery of data stored in cloud services, but they are only effective for frequently accessed data. In this paper, we present an overlay architecture of inter- data center (DC) networking for fast content delivery that is effective for long-tail contents. Based on round-trip time measurements between DCs, content distribution trees (CDTs) are dynamically reconfigured to maximize data transfer throughputs from origin to all other DCs. Furthermore, to enhance throughput by using parallel data transfer on overlay paths (OPs) on a current CDT, a content file are segmented off-line into blocks that are then named at a content server so that each of multiple parallel block-streams can be transferred by an assigned HTTP proxy server at each hop of the OP. Numerical examples obtained by using multiple traceroute servers located in an Asia-Pacific region show that throughput estimates of optimized OPs between some country pair are more than ten times greater than that of direct paths.